Vaginal candidiasis is a yeast infection of the vagina and vulva caused by an overgrowth of Candida, a type of fungus that normally lives in small amounts on your skin and inside your body. It is one of the most common vaginal infections, with the majority of women experiencing at least one episode during their lifetime. It is not a sexually transmitted infection and is not spread from person to person through sexual contact.
What Causes the Overgrowth
Candida yeast exists naturally in the vagina in small numbers, kept in check by beneficial bacteria called lactobacilli. When something disrupts that balance, Candida multiplies beyond what your body can control, and the result is infection. The most common species involved is Candida albicans, though other species like Candida glabrata can also cause infections and may be harder to treat with standard antifungal medications.
Several specific factors tip the balance toward overgrowth:
- Antibiotics: These kill off protective vaginal bacteria along with the bacteria they’re targeting, giving yeast room to flourish. This is one of the most common triggers.
- Hormonal changes: Pregnancy, hormonal birth control pills, and estrogen therapy all raise estrogen levels, which promotes Candida growth.
- Diabetes: Elevated blood sugar creates a more favorable environment for yeast.
- Weakened immune system: Conditions like HIV/AIDS, cancer treatment, or use of steroids and chemotherapy reduce the body’s ability to keep Candida in check.
Sometimes yeast infections occur without any obvious trigger. Having one doesn’t mean you did anything wrong or that your hygiene is lacking.
Common Symptoms
The hallmark symptom is intense itching of the vulva and vaginal opening. Beyond that, you may notice vaginal soreness, redness, swelling, and a thick, white, clumpy discharge often described as resembling cottage cheese. The discharge typically does not have a strong odor, which is one way yeast infections differ from other vaginal conditions.
Pain or burning during urination is also common, usually felt on the outer skin rather than deeper in the urinary tract. Sex can be uncomfortable or painful during an active infection. In more severe cases, the vulvar skin may crack or develop small fissures, and the redness and swelling can be extensive.
How It Differs From Other Vaginal Infections
Several conditions cause vaginal discharge and irritation, so getting the right diagnosis matters. Bacterial vaginosis (BV) is caused by an overgrowth of anaerobic bacteria and a decrease in lactobacilli. It tends to produce a thin, grayish discharge with a noticeable fishy smell, especially after sex. BV rarely causes the intense itching and swelling typical of a yeast infection. Like candidiasis, BV is not an STI.
Trichomoniasis, on the other hand, is a sexually transmitted infection caused by a parasite. It can produce a frothy, yellow-green discharge, a strong odor, and irritation of the cervix and vaginal lining. Because symptoms of these three conditions can overlap, self-diagnosis is unreliable. Studies consistently show that women who assume they have a yeast infection are wrong roughly half the time.
Uncomplicated vs. Severe Infections
Most yeast infections are considered uncomplicated: mild to moderate symptoms, occurring sporadically in otherwise healthy women. These typically respond well to short courses of antifungal treatment, either a cream or suppository inserted vaginally or a single oral antifungal pill.
Severe infections involve extensive redness, swelling, skin cracking, and significant discomfort. These cases tend to respond poorly to short treatment courses and usually require longer therapy. An infection is also considered complicated if it occurs in someone who is pregnant, has uncontrolled diabetes, or has a weakened immune system, because these factors make the infection harder to clear and more likely to return.
Recurrent Yeast Infections
Recurrent vaginal candidiasis is defined as four or more confirmed episodes within a single year. Roughly 5 to 8 percent of women experience this pattern, and it can significantly affect quality of life. The causes aren’t always clear, though some women harbor Candida species that are less responsive to standard antifungal medications.
Managing recurrent infections usually involves an initial treatment course followed by a maintenance regimen of antifungal medication taken weekly for several months. The goal is to suppress Candida growth long enough for the vaginal environment to stabilize. Even with maintenance therapy, some women experience another episode once treatment stops, so the approach sometimes needs to be repeated or adjusted.
Treatment
Uncomplicated yeast infections are treated with antifungal medications available both over the counter and by prescription. Over-the-counter options come as vaginal creams or suppositories in one-day, three-day, or seven-day courses. A single-dose oral antifungal pill is available by prescription and works equally well for most women.
Most people feel significant relief within two to three days, though it can take up to a week for symptoms to fully resolve. If you’ve used an over-the-counter treatment and symptoms haven’t improved after a few days, or if they come back quickly, it’s worth getting tested. You may have a different condition entirely, or a Candida species that doesn’t respond to standard treatment.
Severe infections typically need a longer treatment course, often 10 to 14 days of vaginal therapy or multiple doses of oral medication.
Reducing Your Risk
No prevention method is foolproof, but a few habits can lower your chances of developing a yeast infection. Wearing cotton underwear and breathable, loose-fitting clothing helps keep the vaginal area dry, since Candida thrives in warm, moist environments. Changing out of wet swimsuits or sweaty workout clothes promptly makes a difference for the same reason.
Avoiding douches and scented vaginal products helps preserve the natural bacterial balance that keeps yeast in check. If you’re prone to yeast infections after taking antibiotics, let your prescriber know. In some cases, a preventive dose of antifungal medication alongside the antibiotic course can head off an infection before it starts.